Grasshopper Species Research Articles

Persisting in a windy habitat: population ecology and behavioral adaptations of two endemic grasshopper species in the Cape region (South Africa)

Global biodiversity hotspots are rich in endemic insect species, many of which are threatened by the ongoing anthropogenic pressures on their habitats. The Cape region (South Africa) is one of these biodiversity hotspots, maintaining a high number of endemics. However, the ecology of most insect species in this region remains poorly understood. The two Orthoptera species Betiscoides meridionalis and Betiscoides parva are endemic to the Cape region and specialized on restio vegetation. They are threatened by increasing wildfire frequencies and invasions of non-native plant species. However, this information has been inferred from habitat changes, whereas no ecological study on these species has been conducted since they have been described. In order to facilitate conservation management, information on the ecology of these species is urgently required. The aim of our study was (1) to obtain data on the population ecology (particularly population sizes and mobility), and (2) to study the behavior of both species in response to environmental factors. For this purpose a mark-recapture-study and an observational behavior study were conducted. Both species had small population sizes and a low mobility with males moving greater distances than females. Wind had a strong influence on the behavior of Betiscoides, particularly on the small males of B. parva. Future studies might thus focus on the question whether wind-exposure is a critical factor for habitat choice of this species. We strongly recommend enhancing the connectivity of restio habitats and restoring these habitats to prevent extinction of specialized insect species.

Isolation and characterization of polymorphic microsatellites in the specialist grasshopper Ramburiella hispanica (Orthoptera: Acrididae)

We describe 12 polymorphic microsatellite markers for Ramburiella hispanica (Orthoptera: Acrididae), a specialist Mediterranean grasshopper that often forms highly fragmented populations due to extensive clearing of natural vegetation for agriculture. Polymorphism at these loci was evaluated in 20 individuals from La Mancha region, Central Spain. The number of alleles per locus ranged from 7 to 19 and their observed and expected heterozygosities ranged from 0.41 to 0.90 and from 0.76 to 0.91, respectively. These loci will be highly useful for the study of the genetic structure and diversity of this grasshopper species and understanding the demographic and genetic consequences of population fragmentation in Mediterranean terrestrial organisms.

Mesoherbivores affect grasshopper communities in a megaherbivore-dominated South African savannah

African savannahs are among the few places on earth where diverse communities of mega- and meso-sized ungulate grazers dominate ecosystem functioning. Less conspicuous, but even more diverse, are the communities of herbivorous insects such as grasshoppers, which share the same food. Various studies investigated the community assembly of these groups separately, but it is poorly known how ungulate communities shape grasshopper communities. Here, we investigated how ungulate species of different body size alter grasshopper communities in a South African savannah. White rhino is the most abundant vertebrate herbivore in our study site. Other common mesoherbivores include buffalo, zebra and impala. We hypothesized that white rhinos would have greater impact than mesoherbivores on grasshopper communities. Using 10-year-old exclosures, at eight sites we compared the effects of ungulates on grasshopper communities in three nested treatments: (i) unfenced plots ('control plots') with all vertebrate herbivores present, (ii) plots with a low cable fence, excluding white rhino ('megaherbivore exclosures'), and (iii) plots with tall fences, excluding all herbivores larger than rodents ('complete ungulate exclosures'). In each plot, we collected data of vegetation structure, grass and grasshopper community composition. Complete ungulate exclosures contained 30% taller vegetation than megaherbivore exclosures and they were dominated by different grass and grasshopper species. Grasshoppers in complete ungulate exclosures were on average 3.5 mm longer than grasshoppers in megaherbivore exclosures, possibly due to changes in plant communities or vegetation structure. We conclude that surprisingly, in this megaherbivore hotspot, mesoherbivores, instead of megaherbivores, most strongly affect grasshopper communities.

Morphological and molecular identification of acridid grasshoppers (Acrididae: Orthoptera) from Poonch division, Azad Jammu Kashmir, Pakistan

The present study was conducted to resolve conflicts in the identification of grasshopper species of the family Acrididae (Orthoptera) on the basis of morphology and DNA barcoding. Grasshoppers representing 26 species of the family Acrididae were collected from different habitats and host plants from Poonch division of Azad Jammu Kashmir, Pakistan. Specimens were identified taxonomically and DNA sequenced for the cytochrome c oxidase (COI) barcode region. Barcodes of 19 morphological species were successfully obtained and the sequence data was used to separate species by Neighbor-Joining cluster analysis. Barcode data successfully discriminated 18 species, while two: Patanga japonica (Bolivar, 1898) and P. succincta (Johannson, 1763) could not be distinguished since they shared the barcode sequence and clustered together on the Neighbor-Joining (NJ) tree. Morphologically, specimens of Shirakiacris shirakii (Bolívar, 1914) were identified as one species, but barcode data revealed that in addition to Shirakiacris shirakii (Bolívar, 1914) two other species of the genus Shirakiacris are present in the region. Similarly, on the basis of morphological characters two species were indentified in subfamily Catantopinae, Catantops erubescens (Walker, 1870) and Xenocatantops brachycerus (Willemse, 1932), but barcode data suggest the presence of an additional Catantops species in the region. These findings show the usefulness of barcode data in discriminating grasshopper species and indicate that such data can be reliably used for developing reference libraries for species identification via sequence matches.

Grazing intensity affects insect diversity via sward structure and heterogeneity in a long‐term experiment

Summary In the past, insect diversity in grasslands showed a severe decline due to management intensification or abandonment. In this study, we investigate the long‐term influence of grazing and the potential for spatial patterns created by different grazing intensities to enhance insect diversity. In a long‐term experiment (2002–2011), three grazing intensities were applied to 1‐ha paddocks in a triplicate block design: moderate grazing (MC), lenient grazing (LC) and very lenient grazing (VLC, since 2005). The experiment was conducted in a moderately species‐rich grassland at the edge of the Solling Uplands in Lower Saxony, Germany. Orthoptera (grasshoppers) and Lepidoptera (butterflies) on three 50‐m transects per paddock were counted in 2002–2004 and again in 2010 and 2011. Statistics were performed using linear mixed modelling. Grasshopper diversity measures (species richness and abundance) were significantly affected by grazing intensity; abundance increased from 2002 to 2011 more strongly in the LC than in the MC treatment. Butterfly species richness response to grazing intensity varied among years. Data from 2010 and 2011 did not reveal any advantage of the lowest grazing intensity (VLC) compared to the intermediate grazing intensity treatment (LC) in either insect group. Multiple regressions were used to investigate diversity patterns. Along with compressed sward height, spatial patchiness was important for grasshopper species richness and abundance as well as for butterfly species numbers. Butterfly abundance was mainly influenced by vertical sward height heterogeneity in addition to the significant effects of thistle abundance and number of nectar plant species. Synthesis and applications. Cattle grazing intensity affects the proportions and spatial heterogeneity of short and tall sward patches on pastures. The less mobile grasshoppers particularly benefitted from the structural modifications created by cattle at lenient grazing levels (stocking rate 1·14 SLU ha−1, standard livestock unit (SLU) = 500 kg). In the final study years, areas with intermediate grazing intensity revealed high diversity indices and the most distinct patchiness, therefore a further reduction in grazing intensity is not recommended. This indicates that commercial livestock production may be compatible with conservation targets.

Grasshoppers (Orthoptera: Caelifera) and crickets (Orthoptera: Ensifera) from slopes of Macošská stráň and Vilémovická stráň (Moravský kras Protected landscape area, Czech Republic)

In 2008 we found 21 species of grasshoppers and crickets on Macošská stráň slope and 18 species on Vilémovická stráň slope. Both slopes are located in the northern part of the Moravský kras Protected landscape area and have xerothermic character. Both slopes are influenced by pasture management. For the most comprehensive picture of Orthoptera we used a standard method (sweeping of vegetation) and nonstandard methods (pitfall traps and Möricke yellow cups). Termophilous species of Orthoptera on Macošská stráň (47%) were dominating. On Vilémovická stráň mezophilous species (46%) were dominating. The most common species were Stenobothrus lineatus (Panzer, 1796) on Macošská stráň slope and Chorthippus parallelus (Zetterstedt, 1821), Stenobothrus lineatus, Chorthippus bigutulus (Linné, 1758) and Chorthippus dorsatus (Zetterstedt, 1821) on Vilémovická stráň slope. Rare species of this assemblage were Stenobothrus nigromaculatus (Herrich-Schaffer, 1840) which was on Macošská stráň slope only and Tetrix bipunctata (Linnaeus, 1758) which has much bigger abundances also on Macošská stráň slope.

Population Genetics of the GrasshopperMelanoplus lakinus(Orthoptera: Acrididae) in Durango State, Mexico

Abstract. Melanoplus lakinus (Scudder) is one of the most abundant grasshopper species in the Mexican state of Durango. This state covers a wide semi-desert region of large grassland areas with much biotic diversity, specific orography, and contrasting environmental factors that may affect the genetic structure of the species. Genetics of Melanoplus lakinus populations from seven Durango locations with different biotic and environmental characteristics were assessed. The grassland locations had different plant diversities (ranging from an H' of 1.34 to 3.04) and different proportions of grass. They also have different environmental and orographic conditions. Sixty M. lakinus specimens collected among the locations were analyzed using microsatellites. Three microsatellite markers (OD4, OD7, and OD12) were selected from 11 reported primers. The characterization of loci revealed an average of 28 alleles per locus (range 74–390 bp). The probability of combined non-exclusion was 0.9999, with a mean null allele...

Updated list and community structure of Tettigonioidea and Acridoidea (Insecta: Orthoptera) of the Alta Murgia plateau (Italy)

Alta Murgia calcareous plateau (southeast Italy) is thought to represent one of the most important area for Orthoptera in southern Italy, both due to its biogeographical concern and its unique richness in semi-natural dry grasslands. Since the half of the last century, no recent synthesis has been proposed for the Orthopterofauna of this area and a revision of old observations was still needed. This paper propose a reviewed list of Tettigonioidea and Acridoidea species from the Alta Murgia plateau, also providing information on local community structure and ecology. Based on the revision of previously published lists of species and on data collected during recent field works, a number of 37 species of grasshoppers and katydids is reported. The majority of species found in literature were confirmed, and six species were recorded as new for the area. Data collected during recent field works also enable to provide information about community structure, with particular focus on grassland habitat. This study also gives suggestions for replicable monitoring of Orthoptera assemblages in this area, as it is a valuable information for habitat surveillance purposes and ecosystem conservation strategies.

HP1 knockdown is associated with abnormal condensation of almost all chromatin types in a grasshopper (Eyprepocnemis plorans)

Heterochromatin protein 1 (HP1) is a highly conserved family of eukaryotic proteins required for heterochromatic gene silencing and euchromatic gene transcription regulation. In addition, HP1 is involved in chromatin organization and protection of chromosome integrity during cell division. Here, we present a cytological and molecular analysis of the effects of HP1 knockdown in Eyprepocnemis plorans, a grasshopper species polymorphic for supernumerary heterochromatic chromosomes. Our results revealed contrasting effects of HP1 knockdown on gene activity. While the Bub1 gene decreased in expression level in HP1 knockdown animals, NOR activity, rRNA and, contrarily to previous reports in Drosophila, Hsp70 gene expression remained unchanged. Furthermore, HP1 knockdown resulted in abnormal chromatin condensation, chromosomal bridges, higher frequency of macrospermatids, loss of muscle mass and hemolymph amount as well as a low number of dividing cells and survival reduction. All these phenotypes are very likely due to the chromatin condensation disruption observed for almost all kinds of chromatin.

寄主植物轮换饲养和次生代谢物交叉涂布对棉铃虫取食的影响

Dietary mixing,which means that polyphagous animals prefer to switch the diet items during ontogeny,often affects their growth and developmental performance positively. Two hypotheses,known as nutritional compensation and toxin dilution effect,have been put forward to explain such positive effect based upon the observations of various grasshopper species. As have been demonstrated in many Lepidopterous species,however,polyphagy at the species or population levels do not necessarily imply polyphagy at the individual level,for a caterpillar often has no chance to choose among host plant species due to temporal and spatial separation. In this paper,the authors reported the larvae feeding behavior of a typical generalist species,Helicoverpa armigera( Hubner),by means of forced host-switching( at two hour interval) and crosscoating of secondary metabolites( at natural concentrations) from four common host plant species of H. armigera larvae:tobacco,hot pepper,tomato,and cotton. The results show that,in all the cases,the dietary-mixing did not significantly increase the overall leaf consumption of the fourth instar larvae,moreover,some combinations inhibited feeding amountsand others had no effect,suggesting that nutritional compensation hypothesis could not explain the dietary mixing behavior of H. armigera larvae. Both tobacco leaf and its major secondary metabolite,nicotine hydrate,significantly inhibited the leaf consumption of all the other host species,while neither hot pepper leaf nor its secondary metabolite,( E)-capsaicin,showed effect on feeding amounts of all the other host species. Although tomato leaf in dietary-switching groups did not affect the consumptions of all the other three host leaves,α-tomatine showed significant feeding deterrence when coated on the leaf of hot pepper or cotton. The consumption of tobacco leaf discs increased in cotton-tobacco switching group compared with that in tobacco non-switching group,but the coating of( +)-gossypol on tobacco leaf discs decreased the feeding amounts.Cotton and hot pepper leaf showed no significant interactive effect,neither in force-switching bioassay nor in cross-coating bioassay. Taken together,H. armigera larvae may cope with the secondary metabolites contained in their natural host plants by tolerance strategy,and the tolerance level of an individual larva is in accordance with the symmorphosis hypothesis,i.e.a certain individual larva does not necessarily evolve the mechanisms to adapt multiple secondary metabolites which derived from all the recorded host species.

Orthopteran fauna of the Hel Peninsula in Poland

Grasshoppers and katydids (Orthoptera) were studied on sand dunes of the Hel Peninsula in northern Poland in 2013. Altogether, 11 species of grasshoppers and katydids were identified, three of them can be regarded as elements of the fauna characteristic for sand dunes. Species diversity and population density was higher in the seaside with sparse vegetation than in the neighboring pine forest. The reported low species richness is comparable to other peninsula covered by sand. Myrmeleotettix maculates was most abundant, particularly by the seaside with low shrub sand Tetrix bipuncata occurred frequently in each habitat, but especially on the forest gaps.

Physical mapping of the Period gene on meiotic chromosomes of South American grasshoppers (Acridomorpha, Orthoptera).

The single-copy gene Period was located in five grasshopper species belonging to the Acridomorpha group through permanent in situ hybridization (PISH). The mapping revealed one copy of this gene in the L1 chromosome pair in Ommexecha virens, Xyleus discoideus angulatus, Tropidacris collaris, Schistocerca pallens, and Stiphra robusta. A possible second copy was mapped on the L2 chromosome pair in S. robusta, which should be confirmed by further studies. Except for the latter case, the chromosomal position of the Period gene was highly conserved among the four families studied. The S. robusta karyotype also differs from the others both in chromosome number and morphology. The position conservation of the single-copy gene Period contrasts with the location diversification of multigene families in these species. The localization of single-copy genes by PISH can provide new insights about the genomic content and chromosomal evolution of grasshoppers and others insects.

Stable and variable parameters in courtship songs of grasshoppers of the subfamily Gomphocerinae (Orthoptera, Acrididae)

The courtship behavior of seven grasshopper species of the subfamily Gomphocerinae from different localities of Russia, Ukraine and Greece was described. Not only the sounds but also the corresponding stridulatory movements of the hind legs and visual display accompanying the courtship song were analyzed. Comparison of the degree of variation in different courtship parameters showed that the most stable traits were the syllable and pulse periods. The potential role of stable and variable traits in the grasshopper courtship songs is discussed.

Supercooling capacity and cold hardiness of band-winged grasshopper eggs (Orthoptera: Acrididae).

The band-winged grasshopper, Oedaleus asiaticus Bei-Bienko, is one of the most dominant and economically important grasshopper species in the steppe grasslands and farming-pastoral ecotone in northern China. It is a univoltine species and overwinters as eggs in soil. The cold hardiness of its eggs was examined in the laboratory. Water content in soil significantly affected the supercooling points (SCPs), water content and fat content of prediapause eggs. With the increase of water content in soil, the SCP, and water content of prediapause eggs rose whereas the fat content declined. There was a significant relationship between the SCP and water content or fat content of prediapause eggs. The SCPs of prediapause and diapause eggs varied from −7.6 to −28.4°C and the SCPs of eggs 30 d after oviposition could be divided into two groups. The means of high SCP group (−11.0 to −11.9°C) were much higher than those of low SCP group (−21.8 to −21.9°C), and the majority belonged to the latter (90.48–93.33%). The SCPs of prediapause eggs and early-diapause eggs 30 d after oviposition were significantly higher than those of deep-diapause eggs 60 d after oviposition. The survival rates of diapause eggs were significantly different among different temperature treatments. The survival rate was higher than 88% at greater than −20°C and declined significantly to 57% at −25°C, and suddenly dropped to zero at −30°C. The lower lethal temperature (Ltemp50) for 12 h exposure was −25.3°C and the lower lethal time (Ltime50) at −20°C was 32.8 d. As the mean SCPs of diapause eggs were similar to their Ltemp50, the SCP of eggs can be considered as a good indicator of cold hardiness for O. asiaticus and that this grasshopper is a freeze-intolerant insect.

Switching to Plan B: changes in the escape tactics of two grasshopper species (Acrididae: Orthoptera) in response to repeated predatory approaches

Most studies examining escape behaviour have considered single approaches and single fleeing responses; few have considered how organisms’ response is influenced by persistent pursuit. We explored fleeing behaviour of two grasshopper species to test whether they modified escape behaviour when approached repeatedly. Schistocerca alutacea did not increase flight initiation distance (FID) upon repeated approach but fled farther. Psinidia fenestralis increased its FID on the second approach but decreased its flight distance over successive escapes. Both species showed a bimodal pattern of flight direction, either flying directly away or flying perpendicular to the direction of the observer’s approach. Neither species showed a significant pattern of flight direction or change in flight direction with successive escapes. Most (88 %) P. fenestralis initially landed on sand, but after repeated approaches an increasing proportion landed in grass and hid. Both species therefore changed escape behaviour with persistent pursuit but used different tactics, suiting their flight ability or camouflage, and optimised habitat use. Three grasshopper species have now been examined for responses to repeated approach by predators and all show different tactics supporting escape decision theory. Our results emphasise the variety of escape responses across species and how the dynamic nature of escape responses vary according to an animal’s situation. Rather than single optimum escape options, each grasshopper species shows a range of responses, which vary with risk from persistent predators. Although grasshoppers provide an excellent model, it would be profitable to examine responses of a range of species according to levels of predation risk.

The Orthoptera (Insecta) from Middle and Lower Prut River Basin

Abstract The ecological preferences and bioacoustics of bush-crickets, crickets and grasshoppers species were studied in middle and lower Prut River basin, a research conducted in 55 localities from Romania and 33 localities in the Republic of Moldova. A total number of 91 species of Orthoptera were collected in the study area: 85 species encountered on the western side of Prut River basin (9 Phaneropteridae, 24 Tettigoniidae, 1 Bradyporidae, 5 Gryllidae, 1 Gryllotalpidae, 1 Tridactylidae, 5 Tetrigidae, 39 Acrididae) and 76 species found on the eastern side (7 Phaneropteridae, 19 Tettigoniidae, 1 Bradyporidae, 5 Gryllidae, 1 Gryllotalpidae, 1 Tridactylidae, 3 Tetrigidae, 39 Acrididae). Four species are recorded for the first time in the Orthoptera fauna of the Republic of Moldova: Barbitistes constrictus (Fabricius), Poecilimon fussii Brunner von Wattenwyl, Metrioptera roeselii fedtschenkoi (Saussure) and Pholidoptera frivaldskyi (Herman).

Plant functional traits reveal the relative contribution of habitat and food preferences to the diet of grasshoppers

Food preferences and food availability are two major determinants of the diet of generalist herbivores and of their spatial distribution. How do these factors interact and eventually lead to diet differentiation in co-occurring herbivores? We quantified the diet of four grasshopper species co-occurring in subalpine grasslands using DNA barcoding of the plants contained in the faeces of individuals sampled in the field. The food preferences of each grasshopper species were assessed by a choice (cafeteria) experiment from among 24 plant species common in five grassland plots, in which the four grasshoppers were collected, while the habitat was described by the relative abundance of plant species in the grassland plots. Plant species were characterised by their leaf economics spectrum (LES), quantifying their nutrient vs. structural tissue content. The grasshoppers' diet, described by the mean LES of the plants eaten, could be explained by their plant preferences but not by the available plants in their habitat. The diet differed significantly across four grasshopper species pairs out of six, which validates food preferences assessed in standardised conditions as indicators for diet partitioning in nature. In contrast, variation of the functional diversity (FD) for LES in the diet was mostly correlated to the FD of the available plants in the habitat, suggesting that diet mixing depends on the environment and is not an intrinsic property of the grasshopper species. This study sheds light on the mechanisms determining the feeding niche of herbivores, showing that food preferences influence niche position whereas habitat diversity affects niche breadth.

Coupling historical prospection data and a remotely-sensed vegetation index for the preventative control of Desert locusts

Locusts are grasshopper species that exhibit phase polyphenism resulting in the expression of gregarious behaviors that favor the development of large devastating bands and swarms. Desert locust preventative management aims to prevent crop damage by controlling populations before they can reach high densities and form mass migrating swarms. The areas of potential gregarization for Desert locust are large and need to be physically assessed by survey teams for efficient preventative management. An ongoing challenge is to be able to guide where prospection surveys should occur depending on local meteorological and vegetation conditions. In this study, we analyzed the relationship between historical prospection data of Desert locust observations from 2005 to 2009 and spatio-temporal statistics of a vegetation index gathered by remote-sensing with the help of multiple models of logistic regression. The vegetation index was a composite Normalized Difference Vegetation Index (NDVI) given every 16 days and at 250m spatial resolution (MOD13Q1 from MODIS satellite). The statistics extracted from this index were: (1) spatial means at different scales around the prospection point, (2) relative differences of NDVI variation through time before the prospection, and (3) large-scale summary of vegetation quantity. The multi-model framework showed that vegetation development a month and a half before the survey was amongst the best predictors of locust presence. Also, the local vegetation quantity was not enough to predict locust presence. Vegetation quantity on a scale of a few kilometers was a better predictor but varied non-linearly, reflecting specific biotope types that support Desert locust development. Using one of the best logistic regression models and NDVI data, we were able to derive a predictive model of probability of finding locusts in specific areas. This methodology should help in more efficiently focusing survey efforts on specific parts of the gregarization areas based on the predicted probability of locusts being present.

The genus Xenocatantops Dirsh and Uvarov (Acrididae: Orthoptera) with a new species from northeast China

A new grasshopper species Xenocatantops liaoningensis sp. nov. (Acrididae: Orthoptera) from Liaoning Province, northeast China is described. It is distinguished from Xenocatantops brachycerus (Willemse), and a key to the eight species is included from China. The type specimens are deposited in the Northeast Normal University, Changchun City, Jilin Province, China.

Local climate determines intra‐ and interspecific variation in sexual size dimorphism in mountain grasshopper communities

The climate is often evoked to explain broad-scale clines of body size, yet its involvement in the processes that generate size inequality in the two sexes (sexual size dimorphism) remains elusive. Here, we analyse climatic clines of sexual size dimorphism along a wide elevation gradient (i) among grasshopper species in a phylogenetically controlled scenario and (ii) within species differing in distribution and cold tolerance, to highlight patterns generated at different time scales, mainly evolutionary (among species or higher taxa) and ontogenetic or microevolutionary (within species). At the interspecific level, grasshoppers were slightly smaller and less dimorphic at high elevations. These clines were associated with gradients of precipitation and sun exposure, which are likely indicators of other factors that directly exert selective pressures, such as resource availability and conditions for effective thermoregulation. Within species, we found a positive effect of temperature and a negative effect of elevation on body size, especially on condition-dependent measures of body size (total body length rather than hind femur length) and in species inhabiting the highest elevations. In spite of a certain degree of species-specific variation, females tended to adjust their body size more often than males, suggesting that body size in females can evolve faster among species and can be more plastic or dependent on nutritional conditions within species living in adverse climates. Natural selection on female body size may therefore prevail over sexual selection on male body size in alpine environments, and abiotic factors may trigger consistent phenotypic patterns across taxonomic scales.